Texas Education Code - EDUC § 21.153. Conversion of Probationary Contract to Continuing Contract

(a) A school district that employs a teacher under a probationary contract for the third or, if permitted, fourth consecutive year of service and that elects to employ the teacher in future years under a continuing contract shall notify the teacher in writing of the teacher's election to continuing contract status.  The teacher must, not later than the 30th day after the date of notification, file with the superintendent of the school district written notification of the teacher's acceptance of the continuing contract, beginning with the school year following the conclusion of the teacher's period of probationary contract employment.

(b) If the teacher fails to accept the contract within the period prescribed by Subsection (a), the teacher is considered to have refused to accept the contract.